[Federal Register Volume 82, Number 165 (Monday, August 28, 2017)]
[Notices]
[Pages 40793-40796]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-18169]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
[FWS-R8-ES-2017-N084; FF08EVEN00-FXFR1337088SSO0]
Marine Mammal Protection Act; Stock Assessment Report for the
Southern Sea Otter in California
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of availability; response to comments.
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SUMMARY: In accordance with the Marine Mammal Protection Act of 1972,
as amended (MMPA), and its implementing regulations, we, the U.S. Fish
and Wildlife Service (Service), announce that we have revised our stock
assessment report (SAR) for the southern sea otter stock in the State
of California, including incorporation of public comments. We now make
our final revised SAR available to the public.
ADDRESSES: Document Availability: You may obtain a copy of the SAR from
our Web site at https://www.fws.gov/ventura/endangered/species/info/sso.html. Alternatively, you may contact the Ventura Fish and Wildlife
Office, U.S. Fish and Wildlife Service, 2493 Portola Road, Suite B,
Ventura, CA 93003; telephone: 805-644-1766.
FOR FURTHER INFORMATION CONTACT: For information on the methods, data,
and results of the stock assessment, contact Lilian Carswell by
telephone (805-677-3325) or by email (Lilian_Carswell@fws.gov). Persons
who use a telecommunications device for the deaf (TDD) may call the
Federal Relay Service at 800-877-8339.
SUPPLEMENTARY INFORMATION: We are announcing the availability of the
final revised SAR for the southern sea otter (Enhydra lutris nereis)
stock in the State of California.
Background
Under the MMPA (16 U.S.C. 1361 et seq.) and its implementing
regulations
[[Page 40794]]
in the Code of Federal Regulations (CFR) at 50 CFR part 18, we regulate
the taking; import; and, under certain conditions, possession;
transportation; purchasing; selling; and offering for sale, purchase,
or export, of marine mammals. One of the goals of the MMPA is to ensure
that stocks of marine mammals occurring in waters under U.S.
jurisdiction do not experience a level of human-caused mortality and
serious injury that is likely to cause the stock to be reduced below
its optimum sustainable population (OSP) level. OSP is defined under
the MMPA as ``the number of animals which will result in the maximum
productivity of the population or the species, keeping in mind the
carrying capacity of the habitat and the health of the ecosystem of
which they form a constituent element'' (16 U.S.C. 1362(9)).
To help accomplish the goal of maintaining marine mammal stocks at
their OSPs, section 117 of the MMPA requires the Service and the
National Marine Fisheries Service (NMFS) to prepare a SAR for each
marine mammal stock that occurs in waters under U.S. jurisdiction. Each
SAR must include:
1. A description of the stock and its geographic range;
2. A minimum population estimate, current and maximum net
productivity rate, and current population trend;
3. An estimate of annual human-caused mortality and serious injury
by source and, for a strategic stock, other factors that may be causing
a decline or impeding recovery of the stock;
4. A description of commercial fishery interactions;
5. A categorization of the status of the stock; and
6. An estimate of the potential biological removal (PBR) level.
The MMPA defines the PBR as ``the maximum number of animals, not
including natural mortalities, that may be removed from a marine mammal
stock while allowing that stock to reach or maintain its [OSP]'' (16
U.S.C. 1362(20)). The PBR is the product of the minimum population
estimate of the stock (Nmin); one-half the maximum
theoretical or estimated net productivity rate of the stock at a small
population size (Rmax); and a recovery factor
(Fr) of between 0.1 and 1.0. This can be written as:
PBR = (Nmin)(\1/2\ of the Rmax)(Fr)
Section 117 of the MMPA requires the Service and NMFS to review the
SARs (a) at least annually for stocks that are specified as strategic
stocks, (b) at least annually for stocks for which significant new
information is available, and (c) at least once every 3 years for all
other stocks. If our review of the status of a stock indicates that it
has changed or may be more accurately determined, then the SAR must be
revised accordingly.
A strategic stock is defined in the MMPA as a marine mammal stock
``(A) for which the level of direct human-caused mortality exceeds the
[PBR] level; (B) which, based on the best available scientific
information, is declining and is likely to be listed as a threatened
species under the Endangered Species Act of 1973 [as amended] (16
U.S.C. 1531 et seq.) [the ``ESA''], within the foreseeable future; or
(C) which is listed as a threatened species or endangered species under
the [ESA], or is designated as depleted under [the MMPA]'' (16 U.S.C.
1362(19)).
Stock Assessment Report History for the Southern Sea Otter in
California
The southern sea otter SAR was last revised in 2014. Because the
southern sea otter qualifies as a strategic stock due to its listing as
a threatened species under the ESA, the Service reviewed the stock
assessment in 2015. The review concluded that the status had not
changed, nor could it be more accurately determined. However, upon
review in 2016, the Service determined that revision was warranted.
Before releasing our draft SAR for public review and comment, we
submitted it for technical review internally and for scientific review
by the Pacific Regional Scientific Review Group, which was established
under the MMPA (16 U.S.C. 1386(d)). In a December 6, 2016 (81 FR
87951), Federal Register notice, we made our draft SAR available for
the MMPA-required 90-day public review and comment period. Following
the close of the comment period, we revised the SAR based on public
comments we received (see Response to Public Comments) and prepared the
final revised SAR. Between publication of the draft and final revised
SARs, we have not revised the status of the stock itself (the southern
sea otter continues to retain its status as a strategic stock).
However, we have updated the SAR to include the most recent information
available.
Summary of Final Revised Stock Assessment Report for the Southern Sea
Otter in California
The following table summarizes some of the information contained in
the final revised SAR for southern sea otters in California, which
includes the stock's Nmin, Rmax, Fr,
PBR, annual estimated human-caused mortality and serious injury, and
status:
Summary--Final Revised Stock Assessment Report for the Southern Sea Otter in California
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Annual estimated human-
Southern sea otter stock NMIN RMAX FR PBR caused mortality and Stock status
serious injury
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Mainland............................ 3,194 0.06 0.1 9.58 Figures by specific Strategic.
source, where known,
are provided in the
SAR.
San Nicolas Island.................. 78 0.13 0.1 0.51
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Summary......................... 3,272 .............. .............. 10
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Response to Public Comments
We received comments on the draft SAR from the Marine Mammal
Commission (Commission), Friends of the Sea Otter, and the Humane
Society of the United States. We present substantive issues raised in
those comments that are pertinent to the SAR, edited for brevity, along
with our responses below.
Comment 1: Without adequate observer coverage to document the rate
at which sea otters are being caught in crab and lobster gear, it is
not possible to know if modifications to these traps should be
required. Therefore, the Commission recommends that the Service
collaborate with NMFS and the California Department of Fish and
Wildlife (CDFW) to (1) establish an observer program with adequate
coverage to obtain reliable information on the rate and circumstances
under which sea otters are being taken in crab and lobster trap
fisheries operating within the range of the southern sea
[[Page 40795]]
otter, or (2) implement a precautionary requirement for all trap gear
to be modified to reduce the probability of sea otter bycatch to near
zero.
Response: We recognize that the probability of bycatch in trap
fisheries will rise as the southern sea otter expands its range to the
north, increasing overlap with the Dungeness crab fishery, and to the
south, increasing overlap with the spiny lobster fishery and finfish
trap fishery in southern California. We will continue to work with CDFW
and other partners to assess the best means of testing and, if
appropriate, implementing precautionary trap modifications in the
fisheries that may interact with sea otters. We note that, based on
tests that have occurred to date, relatively minor modifications to
Dungeness crab traps (reducing the fyke opening from 4 x 9 inches (10.2
x 22.9 cm) to 3 x 9 inches (7.6 x 22.9 cm)) would exclude most
independent (post-weaning) sea otters while not impeding the capture of
crabs (Hatfield et al. 2011). Comparable modifications have not been
identified for spiny lobster traps or the large-fyke finfish traps used
in southern California. While observer programs would increase our
opportunity to detect bycatch, analyses indicate that high levels of
observer effort would be required to avoid false-negative conclusions,
even if the rate of bycatch mortality is substantial enough to reduce
the population growth rate (Hatfield et al. 2011). We will continue to
work with USGS, NMFS, and CDFW to explore options for assessing sea
otter bycatch.
Comment 2: Figure 3 in the draft SAR shows an increasing trend in
the number of strandings as a proportion of the spring count of sea
otters (termed ``relative mortality'' in the report), from roughly 5
percent in the late 1980s to 12 percent in the past 4 years. The draft
SAR attributes this pattern largely to the increase in shark-bite
mortality at the peripheries of the southern sea otter's range.
However, this interpretation assumes that search effort and stranding
rates have not increased, an assumption that is not addressed in the
report. The Service should address all of the factors that could
explain the apparent increase in the relative number of strandings.
Response: We have added a discussion of other factors that could
explain the increase in the relative number of strandings and the
relative frequency of shark-bitten carcasses.
Comment 3: The Service should place greater emphasis on the fact
that the ``relative mortality'' rate is an underestimate of the true
mortality rate because a substantial portion of carcasses likely never
strand or are never found, as has been demonstrated in this and other
sea otter populations.
Response: We have added text emphasizing that relative mortality is
an index of mortality and an underestimate of the true mortality rate.
Comment 4: An effective opportunity for public review and comment
cannot occur if the public does not have access to all of the sources
of information used to produce a draft stock assessment. The draft SAR
contains numerous references to sources of information that are not
easily available to the public. The Service should consider
implementing a policy regarding the use of different data/information
sources that would ensure that those sources have been reviewed and are
easily available to the public. The Commission understands that in some
cases the best available science has not been reviewed and published.
In those cases, if the Service uses such information in an SAR, it
should make the information easily available to the public.
Response: We utilize peer-reviewed publications whenever possible.
However, when the best available science on a topic of direct
importance to the SAR has not yet been reviewed and published, we
believe it is preferable to present that information to the public
rather than to withhold it. We may cite an informal source when new
scientific information becomes available and update the citation in a
subsequent revision of the SAR when that information has been reviewed
and published. We have updated several such citations in the final SAR.
Our notice of availability (81 FR 87951; December 6, 2016) includes
contact information, which is made available for the use of anyone
wishing to obtain additional information, including any of the sources
of information referenced in the SAR.
Comment 5: In accordance with section 117(c)(1)(A) of the MMPA, the
Service may review a stock's status annually and update its stock
assessment report only when it considers it appropriate to do so.
However, given the rapid changes that are ongoing within the current
and historical range of the southern sea otter, the failure of the
population to expand its range significantly in the past 20 years, and
the sudden shifts in count trajectories in different parts of the range
over the last few years, the Commission recommends that the U.S. Fish
and Wildlife Service make its stock assessment reviews available yearly
to the appropriate Scientific Review Group (SRG) and the Commission, at
a minimum, from this point forward.
Response: We typically provide a presentation to the Pacific SRG on
the status of the southern sea otter even in years when we determine
that a revision of the SAR is not warranted. We will continue to make
such presentations and, from this point forward, will provide our
reasoning to the Pacific SRG and Commission in years when we determine
that a revision of the SAR is not warranted.
Comment 6: ``Stock definition and geographic range'' must be
expanded to include the importance of range expansion in southern sea
otter survival and recovery.
Response: We have added text emphasizing the importance of range
expansion to recovery of the southern sea otter and referencing Service
documents that discuss the subject in greater detail.
Comment 7: ``Current population trend'' should be revised to
include the declining trend in the southern portion of the range due to
shark bite mortality.
Response: We have added text that describes the regional declining
trends and their relationship to increases in shark bite mortality.
Comment 8: The SAR should identify shark bite mortality as a factor
impeding the recovery of the southern sea otter and encourage the close
monitoring of this significant trend. The Service should confirm that
delisting would not be appropriate even if the delisting threshold of
3,090 animals is met for 3 consecutive years unless the threat posed by
shark bites has been addressed.
Response: We will continue to monitor shark-bite mortality through
the stranding and necropsy programs led by USGS and CDFW, and we have
added text that makes more explicit the relationship between high rates
of shark-bite mortality and the lack of range expansion. However, we do
not believe that the SAR is the appropriate document in which to
discuss threats to the species in comprehensive detail or to make
recommendations regarding delisting. We will update our assessment of
the status of the southern sea otter in relation to the five threat
factors described in section 4(a)(l) of the ESA in the next 5-year
review.
Comment 9: ``Status of Stock'' should be discussed in relation to
the five statutory delisting criteria and the recovery plan, in
addition to optimum sustainable population (OSP) under the MMPA, noting
that OSP has been discussed for the California coast but should also be
considered on a range-wide basis, after accounting for the possible
need to avoid interbreeding
[[Page 40796]]
between northern and southern sea otters.
Response: As noted in our response to Comment 8, we do not believe
that the SAR is the appropriate document in which to discuss threats to
the species in comprehensive detail. However, we have added text that
references our most recent 5-year review (Service 2015). We have also
added text clarifying that a formal determination of OSP will be
developed with reference to the entire historic range of the
subspecies.
Comment 10: ``Habitat issues'' should be revised to include (1) the
spatial structure of southern sea otter habitat and its contribution in
preventing recovery of the species and (2) a detailed discussion of the
risk posed by oil spills.
Response: We have added text clarifying the relationship between
the pace of range expansion, the spatial structure of sea otter
habitat, and oil spill risk. However, as noted in our response to
Comments 8 and 9, we do not believe that the SAR is the appropriate
document in which to discuss threats to the species in comprehensive
detail. We address oil spill risk and the effects of the spatial
structure of sea otter habitat on population growth in our most recent
5-year review (Service 2015). We will update our assessment of these
and other factors in the next 5-year review.
Comment 11: There are recent reports of what appear to be
increasing rates of shooting-related incidents. For example, in 2016
alone there were reports of at least three sea otters being shot. In
2015, a California man was sentenced for shooting an air rifle at sea
otters. While these incidents are more recent than the time period of
the SAR, which is largely through 2014, they do represent the most
recent available information and should be considered for inclusion
since the Service provided information on some deaths as recently as
2016.
Response: We have added text stating that three sea otters died of
gunshot wounds in 2016. However, we do not include these mortalities in
the current calculation of mean annual mortality because they occurred
outside the 5-year analysis window (2011-2015).
Additional References Cited
Chinn, S.M., M.A. Miller, M.T. Tinker, M.M. Staedler, F.I. Batac,
E.M. Dodd, L.A. Henkel. 2016. The high cost of motherhood: end-
lactation syndrome in southern sea otters. Journal of Wildlife
Diseases 52:307-318. doi: 10.7589/2015-06-158.
Lafferty, K.D. M.T. and Tinker. 2014. Sea otters are recolonizing
southern California in fits and starts. Ecosphere 5:50. http://dx.doi.org/10.1890/ES13-00394.1.
Tinker, M.T. 2014. Models and sea otter conservation. Pp. 257-300 in
Larson, S., G. VanBlaricom and J. Bodkin, eds., Sea Otter
Conservation. New York: Elsevier.
Tinker, M.T., and B.B. Hatfield. 2016. California sea otter (Enhydra
lutris nereis) census results, spring 2016. U.S. Geological Survey
Data Series 1018. 10 pp. http://dx.doi.org/10.3133/ds1018.
Authority
The authority for this action is the Marine Mammal Protection Act
of 1972, as amended (16 U.S.C. 1361 et seq.)
Dated: July 26, 2017.
Gregory Sheehan,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2017-18169 Filed 8-25-17; 8:45 am]
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